To determine which species of Culicoides biting midges carry Schmallenberg virus (SBV), we assayed midges collected in the Netherlands during autumn 2011. SBV RNA was found in C. scoticus, C. obsoletus sensu stricto, and C. chiopterus. The high proportion of infected midges might explain the rapid spread of SBV throughout Europe. During early summer 2011, Schmallenberg virus (SBV), a novel orthobunyavirus of the Simbu serogroup, spread across much of northern Europe, infecting ruminant livestock. The Simbu serogroup (family Bunyaviridae, genus Bunyavirus) includes Shamonda virus, Akabane virus, Sathuperi virus, and Aino virus. These viruses cause teratologic effects in ruminants and are arthropod-borne, and most have been isolated in the Old World from mosquitoes and Culicoides spp. biting midges (1). Recent preliminary studies indicate that =1 species of Culicoides midges act as field vectors for SBV in Europe (2). To determine which Culicoides midge species harbor SBV, we analyzed midges collected from 3 livestock holdings in eastern and northeastern parts of the Netherlands.